#include<cstdio>
#include<algorithm>
using namespace std;
int d[10005],n,G,i,j,g,v,last;
int main()
{
freopen("rucsac.in","r",stdin);
freopen("rucsac.out","w",stdout);
scanf("%d",&n);
scanf("%d",&G);
d[0]=0;
for(i=1;i<=G;i++)
    d[i]=-1;
for(i=1;i<=n;i++)
{
    scanf("%d%d",&g,&v);
    for(j=last;j>=0;j--)
    if(j+g<=G)
    {
        d[j+g]=max(d[j+g],d[j]+v);
        if(j+g>last)
            last=j+g;
    }
}
printf("%d",d[G]);
return 0;
}